How can we test a "Unsubscribe" feature of a "Package based system" for mobile company

Let say we have a package "ABC" which expires after every month automatically,
But a user wants to unsubscribe earlier before the expiry date, and for this he has a command "Unsubscribe" which he send through from his mobile phone to the company.
Basically we want to test the "Unsubscribe" functionality of the system. Please share all the possible test scenarios with me. Thanks.